/Engine/Source/Runtime/Engine/Classes/Materials/MaterialExpressionPathTracingRayTypeSwitch.h
class UMaterialExpressionPathTracingRayTypeSwitch : public [UMaterialExpression](API\Runtime\Engine\Materials\UMaterialExpression)
FExpressionInpu...
IndirectDiffuse
Used by the path tracer on indirect diffuse rays
FExpressionInpu...
IndirectSpecular
Used by the path tracer on indirect specular rays
FExpressionInpu...
IndirectVolume
Used by the path tracer on indirect volume rays
FExpressionInpu...
Main
Used for camera rays (or for non-path traced shading)
FExpressionInpu...
Shadow
Used by the path tracer on shadow rays (this only applies for non-opaque blend modes)